Details: Marissa’s first romantic relationship on the show is with Luke Ward. Their relationship begins prior to the Premiere. Marissa and Luke’s relationship stems back to the fifth grade on a class trip to the Museum of Tolerance. After much hesitation, Marissa decides to lose her virginity to Luke. Issues in Marissa and Luke’s relationship constantly arise, making the viewer question if they really are in love. On a trip to Tijuana, Marissa discovers Luke cheating on her with one of her friends, Holly Fischer, on the dance floor in a club. Marissa breaks up with Luke, who later begins an affair with her mother, Julie Cooper. Luke and Marissa’s tumultuous relationship evolves into a mature friendship by the second season. The two realize that they may not be the most compatible couple but can benefit from each other's friendship and support.
Details:Ryan Atwood is the second official boyfriend of Marissa in the series. Although extremely on-and-off- throughout the course of the series - their relationship originated from a Platonic friendship in the pilot episode, which subsequently turned into romantic feelings. From the tenth episode of the first season, the couple officially started their romantic relationship. The beginning of this relationship sees its first end when Marissa feels that Ryan has exaggerated with the friendship between her and Oliver Trask. The second course of their relationship fails due to Theresa Diaz and their illegitimate child, which Ryan agrees to help grow - returning to Theresa's arms and letting Marissa return to her drinking habits. The third attempt of the relationship between Marissa and Ryan ends after the suicide of Johnny Harper where to cry and need a break from each other. The last attempt of a couple's relationship ends when Marissa is killed by a drunken Kevin Volchok who sends Ryan and Marissa's car out of the way, killing the girl instantly.
Details: While Ryan was in Chino, Marissa started a secret relationship with D.J. , The gardener. However, their relationship does not last long, when D.J. he understands that their "relationship" was just a way to make a spit to her mother.
Relationship: Ex-boyfriend / the one who killed her
Details: In the wake of Johnny's death, Marissa struggles to find closure, as well as her own place and purpose in Newport Beach. She develops a relationship with Kevin Volchok after she and Ryan break up, which causes her to go back to her rebellious ways. She begins to abuse alcohol again and tries cocaine. Marissa distances herself from Ryan, Summer, and Seth and becomes argumentative again with her mother. After some time, she comes to her senses and decides to leave Kevin. But when she finds him watching The Sound of Music, she realizes he has a sensitive side and decides she may be able to have a relationship with him. During their senior prom, though, she catches him cheating on her and breaks things off.
In the season finale, Marissa receives a letter from her father inviting her to live for a year on a boat with him in Greece, and she accepts. The day she graduates from Harbor along with her friends Summer, Ryan, Seth, and Taylor, Kevin begins calling her and asks to see her, but she declines. Marissa pays Kevin to get out of town and to leave her and Ryan alone. She says her goodbyes to her family and friends and prepares to leave for Greece. After their time together, Ryan drives her to the airport. On the way to the airport, a drunken Kevin begins hitting their car, causing them to go off the road.
The car flips over several times and lands upside down on another street. Marissa is unconscious, but Ryan pulls her out of the car, which begins to drip gasoline. Ryan takes Marissa into his arms and away from the car as it explodes. He tells her that he will need to go get help, but knowing that nothing can be done, she asks him to stay. After a few moments of looking into each other's eyes, she dies while in Ryan's arms.